Dometic / Atwood 36165 Furnace Low Air Flow Switch (Sail Switch)

Genuine OEM Replacement

Part Number: 36165
Product Type: Furnace Low Air Flow Switch (Sail Switch)
Application: Atwood HydroFlame AF Medium & Dometic DF Medium Model Furnaces

Product Overview

The Dometic / Atwood 36165 Sail Switch (Low Air Flow Switch) is a genuine OEM airflow verification switch designed for select AF Medium and DF Medium series furnaces.

The sail switch confirms adequate blower airflow before allowing ignition. If airflow is restricted due to debris, weak blower output, blocked ducts, or dirty return air passages, the switch prevents the burner from igniting to protect against unsafe combustion and overheating.

If your blower motor runs but the burner will not light, or ignition is intermittent, the sail switch is one of the most common causes.

OEM Part 36165 restores proper ignition sequencing and safe furnace performance.

Key Features

• Genuine OEM Dometic / Atwood replacement part

• Designed for AF Medium and DF Medium model furnaces

• Verifies blower airflow before ignition

• Prevents unsafe burner operation

• Direct replacement for listed compatible models

• Manufactured to original equipment standards

Compatible Furnace Models

Please be aware that there is no precise serial number distinction indicating the transition to the bent blade style in Atwood models, only that this part is suggested for these models with a Serial # above 724XXXXX. It is advised to compare your existing sail switch with the product image for verification. 

AFMD Series

AFMD16111
AFMD16121
AFMD16131
AFMD16141
AFMD16151

AFMD20111
AFMD20121
AFMD20131
AFMD20141
AFMD20151

AFMD25111
AFMD25121
AFMD25131
AFMD25141
AFMD25151

AFMD30111
AFMD30121
AFMD30131
AFMD30141
AFMD30151

AFMD35111
AFMD35121
AFMD35131
AFMD35141
AFMD35151

AFLA Series

AFLA35211
AFLA35221
AFLA35231
AFLA40211
AFLA40221
AFLA40231

AFLD Series

AFLD35111
AFLD35121
AFLD35131
AFLD40111
AFLD40121
AFLD40121W
AFLD40131

DFMD Series

(Serial Number 72489157 and above)

DFMD16111
DFMD16121
DFMD16131
DFMD16141
DFMD16151

DFMD20111
DFMD20121
DFMD20131
DFMD20141
DFMD20151

DFMD25111
DFMD25121
DFMD25131
DFMD25141
DFMD25151

DFMD30111
DFMD30121
DFMD30131
DFMD30141
DFMD30151

DFMD35111
DFMD35121
DFMD35121W
DFMD35131
DFMD35141
DFMD35151

DFLD Series

(Serial Number 72991128 and above)

DFLD35111
DFLD35121
DFLD35131
DFLD40111
DFLD40121
DFLD40131

DFLA Series

(Serial Number 81689156 and above)

DFLA35211
DFLA35221
DFLA35231
DFLA40211
DFLA40221
DFLA40231

Always verify both your furnace model number AND serial number before ordering.

When Should You Replace the Sail Switch?

You may need to replace the sail switch if:

• Blower runs but burner does not ignite
• Furnace attempts ignition then shuts down
• Intermittent heating occurs
• Airflow-related fault conditions appear
• Switch paddle is bent, stuck, or contaminated

The sail switch is one of the most common service parts on AF and DF medium furnaces.

Product Specifications

Manufacturer: Dometic / Atwood
Part Number: 36165
Component: Sail Switch (Low Air Flow Switch)
Application: AF Medium & DF Medium Series
Includes: Sail switch assembly

Frequently Asked Questions (FAQ)

Q: What does a sail switch do?
A: It confirms sufficient airflow before allowing the burner to ignite.

Q: Why does my furnace blower run but no flame appears?
A: A faulty sail switch is one of the most common causes of ignition failure.

Q: Why are serial numbers listed for some DF models?
A: Design updates changed switch compatibility. Units below the listed serial numbers require a different part.

Q: Is this an OEM Dometic / Atwood part?
A: Yes. 36165 is a genuine factory replacement component.